1. Field of the Invention
The present invention is related to compositions and methods for aging of beverages, particularly liquids to be aged in the presence of wood, and more particularly to the accelerated aging of distilled beverages.
2. Description of Related Art
Ethanolic distillates aged in wooden containers exhibit myriad chemical changes over the course of several years. These changes are believed to be due to three types of chemical reactions: 1) reactions involving only the distillate components, 2) extraction of wood-derived compounds that are soluble in the distillate, and 3) reactions of the distillate components with the extracted wood compounds (Liebmann and Rosenblatt, Industrial and Engineering Chemistry, vol. 35, no. 9, 1943). The present disclosure focuses on reactions among the distillate components, including possible reactions of distillate components and extracted wood-derived components and the unexpected results of a novel modification to the chemical milieu that affects the aging process.
Unaged spirits distillates are composed principally of varying amounts of ethanol, acetaldehyde, water, fatty acid esters and ethyl acetate. An average American whiskey (Bourbon) distillate contains about 12 g/100 PL (grams per 100 liters at 100° proof) of ethyl acetate; and malt whiskey, such as that known as Scotch, as much as 29 g/100 PL of ethyl acetate.
During barrel-aging, the predominant transformation in the distillate in quantitative terms is the linear increase in ethyl acetate due to the oxidation of ethanol. Over the lengthy course of barrel-aging, ethyl acetate may increase from three to six times the amount originally present in the distillate (Reazin; American Journal of Enology and Viticulture; vol. 32, no. 4, 1981). In particular, during barrel-aging, ethyl acetate is formed initially from acetic acid already present in the distillate and according to industry investigators, perhaps additionally from acetic acid formed by degradation of the barrel wood. After this initial period, the formation of ethyl acetate is dependent upon the oxidation of ethanol into acetic acid at a uniform, linear rate.
Industry scientific investigators report the mechanism of ethanol transformation during barrel-aging as follows (Liebmann and Rosenblaft, 1943):    1. Ethanol+O2→acetaldehyde    2. Acetaldehyde+O2→acetic acid    3. Barrel wood - - - ↑    4. Ethanol+acetic acid→ethyl acetate+H2O
In conventional barrel-aging, the pH takes about 6 months to drop to the required acidic levels for the various reactions necessary for the development of beverage character to occur. Thereafter, the production of ethyl acetate is dependent upon the formation of acetic acid in the barrel, which takes 36 to 48 months to reach the level of marketable, aged beverages, often 4 years old (Reazin, 1981). It would be desirable in the distillery art to be able to accelerate this process, so that the same character of beverage could be produced in a much shorter time period. The present disclosure provides methods of aging beverages that result in distilled beverages that are aged for much shorter periods, even as short as about 30-40 days or even less, that have the character conventionally achieved only after four years of aging.